Sky Riders is a considerably rare space board game from Parker Brothers. It is dated as a 1940 release in the book American Games (Alex Malloy, 2000) and was featured in a series of advertisements in four consecutive December 1940 issues of Life Magazine. The object of the game is for players to move around the solar system collecting the rare element, Coronium, and then return it to Earth without it being stolen by other players. Bags of Coronium are represented by yellow or green discs. Each player starts with a small coloured wooden token (their Miner). Players move through the orbits of different planets based on the roll of two dice. A player collects Coronium by landing on a planet and then throwing a particular number associated with that planet. When a Miner with five or more bags (discs) of Coronium lands on Mars, it becomes a Martian Raider. The small Miner token is exchanged for a large wooden token of the same colour. The Martian Raider can then capture Coronium from another player by landing directly on the player's Miner. To win the game, a player must arrive back on Earth, by exact count, with 15 or more bags of Coronium.